The present invention relates to tools used for controlled tightening of mechanical members, typically screwed. There are known screwing devices consisting of a body containing the different control or possibly drive members to which are coupled removable inserts designed to engage with the mechanical member on which they are designed to act. By insert is intended here any configuration of a member which can be coupled in a removable manner to the tool to engage in the member with which it is to engage such as a screw head e.g. in the known configuration of a simple sleeve or wrench head.
In this description the term screwing device is used for simplicity of exposition in its broad general sense of device designed to act on a mechanical member to turn it. Accordingly it is intended that among these devices hand operated dynamometric wrenches and powered tools i.e. equipped with electrical or pneumatic generating actuators indicated generally as screwers are to be included. These general screwing devices to which the invention relates are equipped with systems of measurement and control of different parameters related to the operation which they accomplish on the mechanical member engaged by the tool by means of an interchangeable insert. These parameters can be the operation code, the torque, the tightening angle or the like. With the screwing tool are also associated sensing and data treatment and processing systems for presenting data on the parameters to the operator using the manual screwing tool like a torque wrench or even to control the feeding to drive members in powered screwing tools so that they will operated in accordance with the preset parameters.
The operating parameters in accordance with which to act on the member to be tightened which for the sake of brevity is assumed to be a screw are often the univocal function of the size of the engageable part of the member, in this case the screw head. Thus a 13 mm hexagon corresponds to an M8 screw and so forth.
The specific insert coupled with the tool and corresponding to the screw head to be engaged by it has thus a correspondence with the dimension of the threaded screw shank and therefore with the desired screwing parameters. For reasons of speed in screwing parameter setting operations and to avoid errors due to manual setting it has been proposed to collect the inserts which can be mounted on the tool in a magazine or rack where each insert could occupy a single housing corresponding to it. In this manner is created a univocal correspondence between the seat on the magazine (commonly termed `bush changer`) and screwing parameters of the screw on which the insert housable in that seat of the rack is designed to operate.
It is thus possible to equip each magazine seat which collects the inserts with a sensor to detect the taking of the corresponding insert and send insert identification data to the screwing tool to be used for processing the screwing parameters for the screw on which the insert taken is designed to operate.
The system proves to be complicated and the data can be distorted by errors in the coupling between inserts and their seats in addition to requiring the provision of specific univocal couplings between each insert and its bush changer magazine seat, which can even be a limitation on the choice and assortment of the inserts to be used by the user. In addition the entire system of creation of the insert magazine with seats each equipped with a sensor to be wired to the screwing tool control parameter processing circuits is complicated, cumbersome and costly.
The general purpose of the present invention is to provide a screwing tool which can be coupled to a plurality of inserts making up a member for engagement with mechanical members and in which the tool operating parameters can be influenced by the specific insert coupled to the tool which would be reliable, low in cost and not limit the choice and variation of the inserts to be used.